Genetic Genealogy: Parental Phasing Explained

The wonderful DNAeXplained – Genetic Genealogy blog has been posting a series of excellent articles on the topic of genetic genealogy. The one I’m featuring here is on the topic of Parental Phasing using your DNA test results. While it requires plenty of concentration and more than a few steps..it’s an excellent way of working with your DNA test results.

Parental phasing works by comparing your DNA against your matches’ DNA, then comparing your matches’ DNA against your parents’ DNA, and telling you which, if either, or both, parents they match in addition to you.

Oh yes, and there’s one more tiny tidbit – they must match you and your parent(s) on the same segment(s).

The image above is an example of a Matches Spreadsheet. Matches are color coded to better see the match comparison relationships. If Denny (a DNA match) matches both me and my child, you will see a common segment on that chromosome for both me and my child in the spreadsheet. Rows where Denny matches my child are light orange and rows where Denny matches me are light blue, similar to the chromosome browser colors.